Your 'gluten intolerance' might actually be a FODMAP intolerance

There seems to be a "gluten intolerant" person in every group, who looks for the GF symbol on every menu lest some bread leaves them bloated and gassy.

But nutrition experts say Australians need an education in what gluten actually is – because FODMAPs are really the issue for many people who think wheat upsets their stomach.

FODMAP stands for fermentable, oligo-saccharides, disaccharides, mono-saccharides and plypols, which are basically a type of fibre that some people struggle to digest in the small intestine.

Meanwhile, gluten is a protein found in wheat, rye, barley and oats.

"When [FODMAPs] are fermented by the bacteria in the large bowel they produce gas – it all works to expand and stretch the gut wall and that triggers the pain receptors so they sense pain," Dr Jane Muir, head of translational nutrition science at Monash University, told Coach.

"By reducing the FODMAPs you're not generating the gas and having water moving in."

Many products that contain gluten are also high in FODMAPs, so people mistakenly believe it's the gluten that's causing them tummy troubles.

Dr Muir says it's important for people to differentiate between the two because self-diagnosing a gluten intolerance can cause you to miss out on important prebiotics (indigestible fibre that promotes the growth of beneficial gut bacteria).

If doctors have ruled out coeliac disease, a condition which means you absolutely must avoid gluten, then they'll likely diagnose irritable bowel syndrome (IBS), which affects one in seven Australians.

They'll send you to a dietitian who will put you on a low-FODMAP diet for two to six weeks to reset your gut.

"Most of the improvements in gut symptoms come after two weeks on the low FODMAP diet, and then you reintroduce foods slowly," Dr Muir says.

"It's up to people to find their tolerance point. We encourage people not to overly restrict and keep trying to have a bit more of the foods."

The low-FODMAP diet omits foods such as onion, garlic, apple, cow's milk, legumes and many – but not all – wheat products.

"You can have a sourdough spelt bread which is made from the ancient wheat spelt, which is naturally lower in fructans than modern wheats," Dr Muir explains.

"It has got gluten in it but these people can tolerate a bit of gluten. It just so happens that a lot of gluten-free products are low-FODMAP so they get steered in that direction."

For those who blame gluten for giving them a foggy brain, Dr Muir says it might be possible.

"There might be two different things going on – FODMAPs might be part of the story for the bloating and helping the gut symptoms, but if there is something else going on, it's probably something other than FODMAPs," she says.

"It could be something to do with the gluten protein but we don't really know the full story."